Background technology
The seepage prevention system of existing arch dam mainly is made up of dam body seepage and seepage prevention of dam founda curtain.
Dam body seepage mainly relies on the anti-permeability performance of dam concrete self.But, by on the dam facing of upstream, laying certain thickness normal concrete or modified concrete, can strengthen anti-permeability performance, thereby reach the antiseepage purpose for the stone masonry arch dam of the antiseepage scarce capacity of dam body own, rolled concrete arch dam etc.
Seepage proof curtain is that one of building is continuous, complete, permeability is low in basement rock, be the curtain leakage preventing structure of likeness in form curtain wall on ribbon, the facade on the plane." arched concrete dam design specifications " (the power industry standard DL/T5346-2006 of the People's Republic of China (PRC)) 11.4.2 saves regulation: " position of seepage proof curtain line should be arranged in the compressive stress district according to dam foundation stress situation, and near the upstream dam facing." because the compressive stress district of the dam foundation must be positioned in the arch dam dam foundation scope, therefore, afore mentioned rules has been limited in the position that is provided with of seepage proof curtain between the dam heel of arch dam and the toe (shown in this Figure of description 5) beyond doubt.
The foundation of afore mentioned rules is that arch dams heel place causes that for avoiding dam heel cracking seepage proof curtain lost efficacy usually because high tensile stress causes cracking, and cracking position is easily gone up to avoid the dam heel by the compressive stress district that just seepage proof curtain need be arranged in the arch dam dam foundation.At present, when the seepage proof curtain of design arch dam, the compressive stress district that seepage proof curtain is arranged in the arch dam dam foundation has become those skilled in the art's mindset.
Notice of authorization number is a kind of for the utility model patent of CN2672161Y discloses to have an independent dam heel block structured concrete dam.This arch dam makes the stress state of dam heel be improved as compressive stress from tensile stress by transversary seam and the vertical structure seam that is arranged on dam heel place, so that seepage proof curtain is arranged on the below of dam heel.In fact, this scheme does not still overcome the mindset that seepage proof curtain must be arranged in arch dam dam foundation compressive stress district.Publication number is the job practices that the utility model patent of CN101736719A also discloses a kind of dam body seepage curtain.
The utility model content
First technical problem that the utility model solved provides a kind of leakage preventing structure that can avoid causing because of arch dams heel cracking the arch dam that antiseepage was lost efficacy.
The technical scheme that the utility model technical solution problem one is adopted is:
The leakage preventing structure of arch dam comprises being arranged in the basement rock and near the seepage proof curtain of upstream dam facing, this seepage proof curtain is positioned at the outside of dam heel, and its top is connected with antiseepage cap on being arranged on foundation plane; Be provided with structural joint between this antiseepage cap and the arch dam dam body, this structural joint place is provided with the sealing facility.
Further be, the surface of described upstream dam facing is provided with the dam face seepage facility, and this dam face seepage facility extends to from top to bottom near heel back, dam and links to each other with described antiseepage cap.
Further be to be provided with the plasticity inlay sealing material in the described structural joint.
Above-mentioned " antiseepage cap " in fact is exactly a common hydraulic anti-seepage facility, can be poured into a mould by steel concrete, its objective is with seepage proof curtain and sealing facility to constitute the seepage prevention of dam founda system jointly.Because the antiseepage cap is positioned at the top of seepage proof curtain, is similar to a cap-like structure, so be named as " antiseepage cap ".Those skilled in the art can understand the definite implication of this " antiseepage cap " fully according to manual and accompanying drawing thereof.The term of described " sealing facility ", " dam face seepage facility " and " plasticity inlay sealing material " all has precise meaning in this area." dam face seepage facility " can be face slab for water retaining, antiseepage film etc.
Crucial part of the present utility model is, seepage proof curtain has been moved on to the outside of calling in person in the dam (being dam heel upstream side in addition), and seepage proof curtain and antiseepage cap, sealing facility are constituted the seepage prevention of dam founda system jointly.Therefore, the utility model has been broken through the usual thinking that seepage proof curtain must be arranged in arch dam dam foundation compressive stress district.Because the outer rear flank that seepage proof curtain is moved on to dam heel must relate to the connection problem between seepage proof curtain and the dam body seepage, therefore the utility model also related proposed on foundation plane, to set up defences ooze cap, and between antiseepage cap and arch dam dam body, establish structural joint, and the technological means of establishing the sealing facility at this structural joint place, when setting up the seepage prevention of dam founda system, seepage proof curtain is separated with the arch dam dam body, reduce of the influence of arch dam dam body seepage proof curtain.
The utility model is owing to be arranged in dam heel upstream side in addition with seepage proof curtain, therefore avoided the seepage proof curtain damage inactivation problem that dam foundation rock mass cracking causes under the complex loading conditions, the seepage prevention system binding site damage inactivation problem that the while has also avoided the cracking of arch dam dam body and dam foundation rock mass bonding surface to cause; Avoid dam foundation tensile stress to break the seepage proof curtain continuous erosion damage seepage proof curtain of storehouse water later on, caused the problem that basic osmotic pressure strengthens and leakage increases; Avoided seepage prevention system to destroy the problem that worsens dam abutment antiskid stable condition; And the problem of having avoided seepage prevention system destroying infection arch dam general safety.In addition,, changed the osmotic pressure effect, reduced the adverse effect of uplift pressure, helped structural safety because seepage proof curtain is advanced to beyond the arch dam.
The job practices of arch dam leakage preventing structure may further comprise the steps:
A, when carrying out the arch dam dam foundation excavation, expand in the heel outside, the dam of the arch dam that designs and to dig foundation plane;
B, on the foundation plane that expansion is dug out, carry out the construction of antiseepage cap, and the pre-buried sealing facility in structural joint place between antiseepage cap and the arch dam dam body that designs;
C, carry out seepage preventing curtain grouting construction;
D, carry out the construction of arch dam dam body.
Further be that this method is further comprising the steps of:
E, on the dam facing of the upstream of arch dam dam body, the dam face seepage facility is set, the bottom of this dam face seepage facility is imbedded in the antiseepage cap, thereby form the whole seepage prevention system of forming by seepage proof curtain, antiseepage cap and dam face seepage facility.
Further be during implementation step d, to fill the plasticity inlay sealing material in the structural joint between antiseepage cap and arch dam dam body.
By above-mentioned job practices, can build the leakage preventing structure of arch dam of the present utility model.This method makes the construction of seepage prevention of dam founda curtain separate with the dam body construction, can reduce construction and disturb and the mutual restriction problem, for seepage preventing curtain grouting provides enough construction periods, is convenient to Engineering Quality Control, improves the construction operation condition; One need carry out the dam foundation consolidation grouting and handle, grouted cut off wall again can be simultaneously as the upstream control region of consolidation grouting.
The beneficial effects of the utility model are:
One, because seepage proof curtain is arranged in dam heel upstream side in addition, therefore avoided the seepage proof curtain damage inactivation problem that dam foundation rock mass cracking causes under the complex loading conditions, the seepage prevention system binding site damage inactivation problem that the while has also avoided the cracking of arch dam dam body and dam foundation rock mass bonding surface to cause; Avoid dam foundation tensile stress to break the seepage proof curtain continuous erosion damage seepage proof curtain of storehouse water later on, caused the problem that basic osmotic pressure strengthens and leakage increases; Avoided seepage prevention system to destroy the problem that worsens dam abutment antiskid stable condition; And the problem of having avoided seepage prevention system destroying infection arch dam general safety.In addition,, changed the osmotic pressure effect, reduced the adverse effect of uplift pressure, helped structural safety because seepage proof curtain is advanced to beyond the arch dam.
Two, this method makes the construction of seepage prevention of dam founda curtain separate with the dam body construction, can reduce construction and disturb and the mutual restriction problem, for seepage preventing curtain grouting provides enough construction periods, is convenient to Engineering Quality Control, improves the construction operation condition; One need carry out the dam foundation consolidation grouting and handle, grouted cut off wall again can be simultaneously as the upstream control region of consolidation grouting.
Description of drawings
Fig. 1 is the cross sectional representation that the utility model is used for the normal concrete arch dam.
Fig. 2 is the partial enlarged drawing at A place among Fig. 1.
Fig. 3 is used for the arch dam engineering cross sectional representation that stone masonry arch dam, roller compacted concrete soil arch dam etc. need be provided with the dam face seepage facility with the utility model.
Fig. 4 is the partial enlarged drawing at B place among Fig. 3.
Fig. 5 is the schematic diagram of existing arch dam leakage preventing structure.
Be labeled as among the figure: dam body 1, seepage proof curtain 2, antiseepage cap 3, dam face seepage facility 4, sealing facility 5, plasticity inlay sealing material 6, structural joint 7, basement rock 8, foundation plane 9, upstream dam facing 10, dam heel 11.
The specific embodiment
The utility model is described in further detail below in conjunction with drawings and Examples.
Embodiment 1
The leakage preventing structure that is used for the normal concrete arch dam shown in Fig. 1~2, its seepage prevention of dam founda system comprises the seepage proof curtain 2 that is arranged on also close upstream dam facing 10 in the basement rock 8, this seepage proof curtain 2 is positioned at the outside of dam heel 11, and its top is connected with antiseepage cap 3 on being arranged on foundation plane 9; Be provided with structural joint 7 between this antiseepage cap 3 and the arch dam dam body 1, these structural joint 7 places are provided with sealing facility 5.The dam body seepage of this leakage preventing structure then relies on the anti-permeability performance of dam concrete self.In addition, in described structural joint 7, also be provided with plasticity inlay sealing material 6.
This leakage preventing structure adopts following job practices: when carrying out the arch dam dam foundation excavation, upstream side at design arch dam foundation plane 9 digs 2~4m according to row's number expansion of seepage proof curtain 2, carry out the construction of steel concrete antiseepage cap 3 then in the expansion scope of digging, and the sealing facility 5 between pre-buried antiseepage cap and the arch dam dam body 1; 3 constructions of antiseepage cap are finished, and promptly carry out seepage proof curtain 2 grouting constructions; During arch dam construction, establish plasticity inlay sealing material 6 in the structural joint 7 between dam body 1 and antiseepage cap 3, to adapt to the distortion problem of disharmony between arch dam 1 and the antiseepage cap 3.
Embodiment 2
The leakage preventing structure that is used for stone masonry arch dam, rolled concrete arch dam shown in Fig. 3~4, its seepage prevention of dam founda system comprises the seepage proof curtain 2 that is arranged on also close upstream dam facing 10 in the basement rock 8, this seepage proof curtain 2 is positioned at the outside of dam heel 11, and its top is connected with antiseepage cap 3 on being arranged on foundation plane 9; Be provided with structural joint 7 between this antiseepage cap 3 and the arch dam dam body 1, these structural joint 7 places are provided with sealing facility 5.The dam face seepage facility 4 that the dam body seepage of this leakage preventing structure then relies on the surface of upstream dam facing 10 to be provided with, this dam face seepage facility 4 extend to from top to bottom near dam heel 11 backs and link to each other with described antiseepage cap 3." dam face seepage facility " can be face slab for water retaining, antiseepage film etc.In addition, in described structural joint 7, also be provided with plasticity inlay sealing material 6.
This leakage preventing structure adopts following job practices: when carrying out the arch dam dam foundation excavation, upstream side at design arch dam foundation plane 9 digs 2~4m according to row's number expansion of seepage proof curtain 2, carry out the construction of steel concrete antiseepage cap 3 then in the expansion scope of digging, and the sealing facility 5 between pre-buried antiseepage cap and the arch dam dam body 1; 3 constructions of antiseepage cap are finished, and promptly carry out seepage proof curtain 2 grouting constructions; During arch dam construction, establish plasticity inlay sealing material 6 in the structural joint 7 between dam body 1 and antiseepage cap 3, to adapt to the distortion problem of disharmony between arch dam 1 and the antiseepage cap 3; On the upstream of arch dam 1 dam facing 10 dam face seepage facility 4 is set then, the bottom of dam face seepage facility 4 is imbedded in the concrete of antiseepage cap 3, has promptly formed by seepage proof curtain 2, antiseepage cap 3 and dam face seepage the 4 whole seepage prevention systems of forming are set.